


Trails of Fire

by myownpersonaldemons



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), F/M, POV Second Person, Smut
Language: English
Status: In-Progress
Published: 2019-12-10
Updated: 2020-01-20
Packaged: 2021-02-18 07:33:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 9,002
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21740695
Author URL: https://archiveofourown.org/users/myownpersonaldemons/pseuds/myownpersonaldemons
Summary: A collection of one-shots featuring our favourite firey bar owner in Underfell, Grillby!----Mostly all of these were originally posted on my tumblr, as a majority of them are requests.
Relationships: Grillby (Undertale)/Reader
Comments: 14
Kudos: 155





	1. Quiet Or They'll Hear*

**Author's Note:**

> These won't _all_ be smut, there are a few non-smut one-shots as well that are more fluff and stuff, or just requests from tumblr users. I'll post in the beginning of the chapter if it was a request and who requested it (if they weren't anons).
> 
> All of the chapters with * at the end are smutty!

You giggle at the antics you were getting up to in your game, hearing your friend snorting in their laughter. It was ridiculous moments like this that made you miss being able to play with your friends more often. While playing alone could be almost cathartic in a way, there was something about running around and _not_ doing what you were supposed to in favour of finding out the dumbest things to do.

“ _One sec, I gotta go feed the dogs and let them out_ ,” your friend said before you heard the tell-tale sign of them placing their headset down and then a faint, “ _Is it din-din time?”_ before you listened to the skittering of nails on the ground as their dogs booked it after them.

You snorted and opened your inventory, deciding to take the time to organize your inventory and get rid of some unwanted items. You hummed quietly and kicked the blanket off your lap as you grew warm. Which was strange since the window was cracked open, and the cold air was drifting in, making your fingers slightly chilly. It wasn’t until two hot hands settled on your shoulder and began to massage them.

You glanced up to see your purple boyfriend grinning down at you in a very…salacious way.

“What?” you said, returning your gaze to the television.

“Can’t I want to give you a shoulder massage with no ulterior motives?” he asked, fingers digging in just the right way. Your eyelids fluttered shut slightly, and you groaned in delight as you felt your tense shoulder muscles starting to relax.

“The fact that you said ‘no ulterior motives’ means you have them,” you teased in response, tilting your head to kiss his knuckles. He chuckled, and then his hands left your shoulders. For a second, you really did think you had pegged him wrong, but then he moved around to settle on the sectional in front of you.

His hand slid up your calf to rest on your knee and then he gently started shifting your legs apart. Your face flared and you tightened your legs together. “Grillby, I’m playing with my friend,” you gestured towards the television. “Later.”

He grinned, and then very quietly whispered, “Then you just have to keep quiet. Won’t you?”

Your face heated up even more at that prospect, but his hand didn’t move to shift your legs apart again. Instead, he just stared at you with a big grin on his stupidly handsome face. You hesitated before closing your eyes and sighing. Were you seriously considering this?

“Fine,” you bit out quietly.

His grin grew, and his hands moved to your pyjama pants, hooking over your waistband and pulling them down your legs. You clenched your jaw shut, face on fire as you tried to return your attention to the television.

Grillby pushed your legs apart, and you let one shift off the couch, resting your foot on the ground. The other one he quickly hooked over his shoulder. He peppered small nips along the inside of your thigh that had you quickly almost panting as you exited the inventory and hit the button to make your character start dancing as you waited for your friend to come back. You focused on keeping your breathing as even as possible, even as your boyfriend’s mouth started to work, its magic. Your head was spinning even before your friend returned from feeding their dog.

You heard the clattering as they picked up their headset, and you felt a spike of heat go straight between your legs, followed by your boyfriend's heated chuckle as clearly felt the effects.

 _“Anyways, we should probably go and do one of the missions now, yeah?”_ they asked.

“Y-Yea-“ you cleared your throat, “Yeah. Sorry, throats super dry.”

They laughed, _“Get some water then, I can wait.”_

“No, it’s fine,” you said quickly and bit your lip as a moan threatened to work its way through you as Grillby changed pace and intensity. You glanced down, meeting his gaze and had to mask a heated groan as a reaction to how far you and your friend had to walk to get to the next part. The banter was harder than you thought it was going to be to keep up while your boyfriend had his head between your legs.

You felt your orgasm building and building, and you had to shove your shirt into your mouth and focus more on your breathing than you should when playing a game. Then Grillby’s mouth left you, and he sat up. You glanced at him, almost disappointed that he had stopped when he reached for his zipper. He paused, giving you a look, and you nodded, bucking your hips slightly, and he grinned.

“ _Normally, I’m the one who sucks at video games!”_ your friend commented as Grillby lined himself up, teasingly pressing against you, not hard enough to actually enter you.

“Sorry! My mind must be…elsewhere,” you said, hoping they didn’t notice how breathless the last word was. They didn’t as they immediately shouted in alarm as they died.

Grillby slowly pressed into you, and you didn’t dodge out of the way in time before you were killed. You swore more from the feeling of Grillby slowly filling you rather than dying in the game, but your friend mimicked the swear. Thankfully, you were able to focus on Grillby pressing completely into you, the delicious stretch, for a few extra seconds as the load time to back to the entrance to the area was longer. Grillby grinned before pulling entirely out of you.

He sat down on the couch and patted his lap. You gave him a look and gestured towards the screen.

“So you can see better,” he whispered, “Don’t want you dying too much.”

You pressed your lips into a thin line before standing up and standing in front of your boyfriend. “One second, I just want to check my gear first,” you told your friend, opening the inventory menu and temporarily muting your mic before you reached behind you for Grillby’s cock. You slowly eased yourself down, allowing yourself to moan after double-checking that your mic was indeed muted. Grillby’s hands went to your hips as he rocked up into you, pulling another breathy moan from your lips.

 _“Are you checking your phone instead of your inventory?”_ your friend asked, sounding vaguely impatient.

You swore and turned your mic back on, cursing when Grillby intentionally thrust up into you. “S-Sorry,” you said, quickly exiting out of the inventory. “Grillby was bothering me.”

Grillby nipped your shoulder, letting you know exactly what he thought of that comment; you merely grinned and ground your hips down into his. He took over the pace, arms slipping under your thighs, fingers digging into your skin as he effortlessly lifted you on and off his dick.

You focused as best you could on the game, but when you once again died you let out a groan of frustration. “I guess I’m just not in the zone tonight,” you said, half-lying as you swallowed down yet another moan. Grillby’s mouth began kissing up and down your neck, occasionally licking the flesh there, making you shiver.

“ _Yeah, you seem really out of it. We can try again tomorrow! I should probably go get ready for work anyways. Night shifts are the worst,_ ” they groaned as they exited the game. You nodded.

“Sure! Text me when you wake up and-,” you pressed your hand over your mouth as Grillby let your feet rest on the ground again before bending you forward. The angle hit you in just the right spot, making you see blissful stars. “We can…decide something then,” you managed to choke out.

_“….you okay?”_

“Yeah, stubbed my toe,” you lied, “Fuck.”

“ _Shit, that’s gotta hurt. I’ll let you go! Talk to you later,”_ they called, and you managed to call out a goodbye before you quickly shut down your console. Before it was fully off, you were grasping at Grillby’s hands on your waist, your controller falling to the floor, and you let out the loudest moan you’d ever made. Grillby groaned at the sound and his pace increasing, thrusting up into you hard and fast.

His arm snaked around your waist and yanked you back upright, pressed against his clothed chest. After being forced to not make a sound, it was as if you were incapable of not making sounds now. You were panting, moaning, begging, and saying his name over and over again as you bounced up and down on his cock. When his hand slid back between your legs, you lost it.

Your stomach clenched and your fingers dug into his skin as you shouted his name. You saw white.

As you came down, he petted you through it with gentle touches. He nibbled lightly on your ear, before chuckling.

“You surprise me,” he admitted, as you shakingly stood up.

“Y-Yeah?” you said, wobbling a bit when you took a step. Grillby easily lifted a hand to support you.

“Thought you’d be moaning my name into the mic, kinda disappointed you didn’t,” he chuckled, “but fucking impressed that you didn’t. We should do that more often.”

You gave him a glare with no heat, “next time we do anything like that, it’s going to be _you_ moaning inappropriately.”

Grillby gave you a Cheshire grin, “If you’re into exhibition, I bet I can find someone who’d pay to watch us fuck.”

You snatched your pyjama bottoms off the couch and covered your face with your other hand. “No fucking way!” you said blushing deeply, then you peeked down at him. A stray thought popped up into your mind and you reached over, placing your fingers on his chin and tilting his head up to look at you. “Besides, the only person I want to hear me moan is you, my love.”

That got exactly the reaction you wanted, his eyes brightened and his flames snapped in the way they always did when he was pleased. His flames tinted a bit blue at being called ‘my love’ as they always did when you said ‘love’ or anything of the sort. He grasped your wrist and kissed your fingers. “I’m the only one who gets to make you moan,” he retorted, but his voice was a bit…crackly. He started kissing up your arm, slowly standing as he did until he kissed up your neck and pulled you into a breath-taking kiss.


	2. Babysitter Extraordinaire

**Notes for the Chapter:**

> No smut, and not a request!
> 
> I was chatting with a friend on discord and we were talking about how UF!Grillby would handle being around kids, thus this was created!
> 
> Enjoy!

“Hm…fuck no? Is that a good answer?” Grillby said, crossing his arms and shifting his weight back away, effectively closing himself off. You leaned against the table, pressing your lips together. That was precisely the kind of reaction you were expecting to get, honestly, but you were going to give it your best attempt instead of letting the topic slid there.

“It’s only for a week, and I’ll be the one looking after ‘em. I’m their last resort, anyways! Everyone else is either busy or doesn’t have the time,” you explained, allowing your voice to take on a hint of begging. You may be proud, but with your boyfriend, you weren’t above begging. He rolled his eyes, or the approximation of the action as he didn’t have eyes really to roll.

“I don’t care if you were the last person on Earth,” Grillby gritted out, “I am not allowing a kid into this apartment.”

“Why not?”

“Five reasons,” Grillby held up a hand, he lowered one finger per excuse. “One, I hate kids. Two, they’re messy and sticky and get shit everywhere. Three, I can’t swear in front of them. Four, a week with a kid in the apartment means a week where I can’t have sex. Five, what would Sans say if his bedroom was occupied?”

You held up your hand, and with each counterpoint, you raised a finger, “One, you don’t hate kids; you don’t know how to act around them. Two, she’s _not_ a messy kid. Three, you can swear in front of her since her parents do. Four, we can still have sex; we just got to get creative and make sure the bedroom door is locked. Five, if you’re really that concerned about Sans’ sleeping arrangements, he can sleep with us in our bed when he gets blackout drunk.”

He scowled at you for that last one, then ran a hand down his face, “Why do you care? Can’t they just hire some nanny or some shit like that?”

“Not everyone’s as rich as you, Grillby,” you pointed out.

“What if _I_ hire someone for them instead?” he gestured to himself.

“I don’t trust you to hire someone with the right credentials,” you admitted, giving him an apologetic grin.

That had been a massive blow in his ego, but eventually, you had gotten him to agree to babysit your sister's kid for a week. Not a day more. You honestly weren’t excited to take care of a kid for a week, but it was for your sister, and she’d owe you big time for this. You had kissed him and thanked him, saying that you owed him. He grumbled about it and was still complaining about it.

Especially, because you had subsequently gotten really fucking ill the day after your sister dropped off your niece. You had woken up dizzy and sweating. Grillby had taken one look at you, sworn, and taken you to the doctor. He’d almost forgotten to bring your niece as well, and you weren’t in any mindset to actually remember. You could barely remember how to zip up your jacket, let alone that you had a small child to look after. Your niece was cuddled up in your arms in the waiting room as your boyfriend sat with his head in his hands.

“Sorry,” you mumbled, leaning against him, the simple act felt way too much for you.

“It’s not your fucking fault,” he replied, turning and kissing your forehead. It surprised you. He usually wasn’t an affectionate person in public, well not that sort of affection. Though you were feeling chilled, and the warmness against your forehead was delightful, so you leaned further against him.

Grillby wasn’t used to seeing you so…weak. Pale. Awful. You could barely hold onto the child in your arms as the three of you walked back to the car. So, Grillby reluctantly held his arms out towards you. You looked at him, tired confusion in your eyes. “Gimme the kid,” he muttered, and you slowly shifted the sleeping kid over into his arms.

Well.

This was weird.

He couldn’t say he liked it.

The child was small and stared up at him with as much apprehension as he stared down at her with. She was stiff as he attempted to hold her like you had been holding her. Then again, that was probably because he was stiff as well. With a grimace, he shook off the awkwardness of the situation and placed a hand on your lower back and guided you over to the car. You were ill, and you needed antibiotics for the next week until whatever this was had passed.  
Which meant, instead of _you_ looking after the kid.

_He_ was going to have to look after a child that wasn’t his, _and_ look after his sick girlfriend.

He didn’t mind the latter of those responsibilities, but the first? He didn’t care for your sister too much and thought her husband was a bastard, so looking after their child was not something he wanted to do at all. He’d only allowed the kid to be in your apartment because you said you’d take care of her.

With a sigh, he fumbled with the car seat until you brushed him aside and did it before you got into the front seat. By the time he got to the driver's seat, you were well on your way to passing out, arms crossed and slumped in the seat.  
He hoped to the stars that you would be lucid enough to tell him at least what to do, and deal with the kid while he was at work. Grillby was _not_ going to miss work because of a dumb kid.

When he pulled into the parking stall, he nudged you gently awake. You blinked sleepily before getting out of the car. He worried when you swayed slightly. Then he was hit with the sudden need to get you away from everyone's eyes. So, he scooped the kid out of the car as fast as he could and got you onto the elevator. You were weak. Defenceless. Not only that, but there was also the vulnerable, defenceless child. At least with the kid, he knew none of his enemies would bother with it. No one would harm kids, after all.

The panic about your safety faded the moment he locked the door to the apartment.

You fumbled with your zipper, and he assisted you in getting your winter gear off before handing you the kid. You stared at the kid for a second and then looked up at him confusedly. “What?”

Fuck.

Just what he needed.

“I don’t know how to take off the snowsuit shit you put on her,” Grillby said, giving the baby a small wiggle. She giggled and kicked her feet.

You made an ‘oh’ noise before reaching forward and taking the kid from him. He breathed out a sigh of relief as you worked the snowsuit off the kid. Grillby watched you as you talked to your niece cheerfully, even exhausted and sick as all hell you were still super sweet and cute to a kid that wasn’t even your own. You stood up, wobbly, and he quickly placed a hand on your back to steady you.

“You should rest,” Grillby pointed out, “I don’t want to have to take you back to the doctor because you cracked your skull open.”

“I’ll be fine. I got medication,” you retorted, waving a hand and scooping up your niece. “Plus, I said I’d look after Alex, so look after her, I will.”

Grillby didn’t bother fighting you but kept a close eye on you and the kid. He lounged on the couch with a book so that he could keep an eye on you as you did various activities with the kid. At one point, the chubby little shit got up and headed over to him and held up a crayon drawing. He looked at it and then glanced back at you. You looked even sicker than you had earlier, but you gave him a thumbs up.

“Looks good,” he muttered, “What is it? An eggplant and a potato?”

“It you,” the kid pointed at the purple shaped object, “n’ auntie.”

You giggled at that, but in a way that made him realize that you were becoming loopy. Grillby sighed, biting back his normal saucy response and instead sat up. 

You should sleep,” he said, directing his attention towards you. You rolled onto your back on the ground.

“Gotta watch Alex,” you replied, giving him another thumbs up.

  
“Doesn’t the kid need a nap too or something? Wasn’t that what your sister said?” Grillby gestured towards the kid who had placed the drawing on his lap and was heading back over to the crayons on the living room floor. He hoped there wasn’t any crayon on the wood. When you just made a fart noise, he sighed and ran a hand down his face. “I’m not _your_ babysitter.”

“I’ll sleep when you go to work,” you said before rolling back onto your stomach and sitting up. “I need to give Alex a bath.”

Grillby sighed deeply before waving a hand, “Don’t drown in the tub. I can’t help you out if you do.”

You stuck your tongue out at him as you got to your feet and scooped up Alex. She complained as you disappeared into the bathroom, leaving him alone in the living room. He checked his watch. A little over two hours before work. He could go early to get everything ready, but he didn’t really feel comfortable leaving you alone while you were sick. So, he listened carefully, hearing the kid complaining about not wanting a bath fading into giggles from both you and the kid.

Eventually, he got up and peeked into the bathroom to ask what you wanted for dinner.

You were drying the kid off, a fond look on your face as you booped her on the nose.

“What do you want for dinner?” he asked, shoving down the strange fluttering in his SOUL at that sight. He didn’t have time to unpack it, and quite frankly, he didn’t care to at all. Cus, fuck that.

“Something light,” you replied, tucking the blanket around the kid. “I don’t know if I can hold anything too heavy down.”

He nodded and headed into the kitchen. When he finished, he went to find you to let you know that he’d made some soup, but he was met with the sight of you passed out on the bed with Alex flipping through one of the books her mother had left with them. Grillby sighed heavily. Great. Could he even leave you alone with the kid tonight? His bar was open for nine hours…

Closing his eyes, he rubbed at them roughly for a second.

Then he stepped out of the room and called up Sans.

“to what do i owe the pleasure?” Sans said as he answered the phone.

“Come to my apartment,” Grillby practically ordered before hanging up.

It took longer than Grillby would’ve liked before Sans popped into existence in the middle of the living room. Sans scratched at his skull, staring down at the crayons and papers were still strewn about. “arts n’crafts grillbz? didn’t take ya for the kind of monster.”

Grillby explained the situation simply instead of allowing himself to rise to the bait. “I need you to make sure neither of them ends up killing themselves.”

“what? no.” Sans held up his hands, “i ain’t a babysitter.”

“I’ll cut your tab in half,” Grillby insisted, and saw Sans’ face twitch.

A second passed, and then Sans groaned, “fine, fine. i’ll make sure they don’t off themselves.”

“Good,” Grillby said and then placed a hand on Sans’ jacket. The scent of burning cloth rose up, “If even a hair on their head is injured-“

Sans shrugged off Grillby’s hand, “ya trust me ‘nuff ta look after yer mate and a kid, and i ain’t about to break that trust, grillby.”

Grillby nodded stiffly before turning and heading back into the spare room. He carefully picked you up from the bed and brought you into your actual bedroom. After waking you up briefly to explain what was happening, giving you medication, he tucked you into bed and headed back out. 

Alex was staring at Sans with as much apprehension as a little kid could have.

“I’ll be back at two sharp,” Grillby informed Sans as he pulled on his jacket.  
Alex trotted over and tugged at Grillby’s hand. “I go too?”

“No?” Grillby pulled his hand from Alex. As he turned, the little girl tugged at his hand again.

“I go too.”

“No.”

“Yes.”

“No.”

“Yes.”

Grillby picked up Alex, holding her at arm's length and strode over to Sans. He placed her beside him. “Stay.”

“Go!”

He ignored her and left.

Sans looked down at the kid, who was glaring after Grillby. Then, she burst into tears.

You woke up the next morning, feeling a bit more clear-headed. You pushed yourself up slightly, groaning. Okay, strike that. You were aching. You probably should take a warm bath, or get a massage from Grillby to help with the aches and pains. Speaking of…Grillby wasn’t lying beside you, which was strange. He always slept in later than you, as he didn’t need to work until later in the day. You slowly got out of bed, pulling on a sweater to fight off the chill, and left your bedroom.

Grillby was cooking pancakes in the kitchen, and Alex was babbling away to Grillby as she ate some mashed fruits messily.

The apartment was an absolute nightmare.

“What happened?” you asked, looking at all the toys, books, dishes and everything strewn about.

“Sans is never allowed to babysit for me again,” Grillby spat out, gesturing towards the mess, “Sure, you two didn’t die but! The apartment’s a fucking nightmare!”

“Fucking!” Alex mimicked and then held up her spoon towards Grillby.  
He stared at it for a second, and only after she offered it to him again, he sighed and bent down and accepted the mashed fruit with only a bit of reluctance. You fought the smile on your face.

“I’ll clean up-“

“You are sick, sit your ass down,” Grillby said, “I can clean the apartment.”

You hesitated but sat down in the chair at the island that he gestured to. Alex was sitting on the counter, which if Grillby wasn’t the one watching her, you might’ve had an aneurysm. You knew your sister would if she saw it, but you weren’t going to tell her. Alex scooped up some more fruit and offered it to you. You shook your head, “I’m sure Uncle Grillby would love some, though.”

You saw Grillby’s flames snap oddly at being called Uncle, and he gave you a look, “Just Grillby.”

“Jus’ Gwillby,” Alex repeated but offered the spoon towards Grillby again. He once again, reluctantly accepted the food. Then he put a smaller pancake on a plate and placed it in front of her.

He made a slightly bigger one for you, and you didn’t know if you should eat it…but you did because you’d never turn down Grillby’s cooking. As you and Alex ate, he explained how he had left Sans in charge when he went to work, and that he had come back to Sans passed out on the couch, Alex passed out in the bathroom with the faucet running. You had apparently attempted to get out of bed at one point but decided that walking was too much energy and had curled up on the floor in the hallway. He’d kicked Sans out, and put you and Alex to bed. Last night he’d been to just exhausted to deal with the mess that was the apartment but insisted that it had been _worse_ when he had gotten home.

You apologized once more, and he just gave you a blank look. “You’re sick, again, not your fault. You owe me big time, but not your fault.”

You smiled, “Course, you’re the best boyfriend ever.”

He puffed up slightly as you fed his ego with just those few words.

Thankfully, that was the last fiasco. Your medication was helping, and you had a clear enough head for the rest of the week to look after Alex when Grillby went to work that you didn’t need a babysitter in the form of Sans.

Grillby wasn’t anywhere close to what you’d call affectionate with Alex, but he seemed to tolerate her enough that sometimes their interactions were cute. At one point, she wanted to know what he was reading, so he read out loud to her as she sat beside the couch and peered up at the book. When she tried to crawl into his lap, he picked her up and gave her to you instead. The one time that Alex woke up from a nightmare and snuck into your room, he had been startled as the tiny form crawled over him and nearly fell out of the bed. You’d merely groggily asked her what was wrong before allowing her to cuddle up next to you for the rest of the night.

When your sister finally came to pick Alex up, you had smiled and said everything went swimmingly. No issues. You totally weren’t sick. Grillby totally didn’t at one point let her try a sip of his whisky, and she totally didn’t pull the ‘ew gross’ face before asking for more. She totally didn’t walk in on you and Grillby getting it on because he forgot to lock the door like you had told him. She’d also definitely did not eat an entire crayon. You still weren’t sure if she did, but it was missing from the crayon collection, and you couldn’t find it anywhere.

It wasn’t until a few days later that your sister phoned you up.

“Why is Alex calling her father ‘bastard man’?”

You turned and glared over at Grillby. “I honestly have no idea why Alex is calling your husband a bastard. Grillby????”

Grillby merely gave you a grin that was reminiscent of the knife cat meme.

So close to your sister, thinking you were the best babysitter.

So close.


	3. First Time*

**Notes for the Chapter:**

> This was a request from an anon over on tumblr about getting a full explicit scene from Chapter 27 of my Self-Tober prompt story!

Waking up in the middle of the night wasn’t uncommon anymore. After all, your boyfriend generally would come to your place at three am after he was finished work just so he could sleep next to you. So, your body just started to wake up naturally anywhere from two-thirty to three-thirty. Tonight was no exception. Except for this time, your mouth was sandpaper dry.

That’s what you get for not drinking water before bed.

You groaned, flopping your arm over and patting around until you found your phone. A few minutes until three.

Maybe you could wait until Grillby came over and you could text him to bring you water?

…

Ha.

He never touches the stuff.

You rolled out of bed, not bothering to turn on your bedroom light (but definitely the kitchen light) and shuffled over to the kitchen. As soon as your hand plucked the glass from the cupboard, you heard the soft click of the apartment door opening. You watched over your shoulder as Grillby quietly entered your apartment, quietly shut and locked the door, and very quietly hung up his jacket.

His fingers deftly begun to remove his bright red tie as he turned around. The moment his eyes met yours, he started, his light whooshing a bit brighter.

Not that he would ever admit you startled him.

“You’re awake? Missed me that much?” he teased striding over to you all confidence. He was wearing that black button-up shirt that had faintly shiny thread stitched into it that reflected his flames giving him a certain ‘look at me’ glow. Of course, now unbuttoned.

“Sure,” you replied back, moving to fill your cup with water. He stayed a few paces away. “How was work?”

You weren’t sure if your sentences were loud enough or clear enough, as sleep idled as your mind was, but he seemed to get the point at least. “Boring, dull, tedious, lacklustre, monotonous…” he waved a hand, “Hiring Sans as the bar’s bouncer means I don’t get to have fun anymore.”

You laughed softly at that and finished your water, placing the glass aside to be cleaned. The moment your hands were off the glass, his were on _you_. You felt goosebumps as he pressed a hot kiss to your shoulder, his fingers ghosting along your stomach, the fabric shifting to expose a bit of skin between your tank top and sleep pants. A shiver rolled through you and you felt all the warmth collect and pool between your thighs.

Which wasn’t new. Grillby touching you in this manner always made you squirm, but tonight there was none of that hesitance or voice saying ‘not yet’ in the back of your head.

So, as he peppered your shoulder with kisses, you took his wrist and gently pushed it further down. There was no resistance from him until just before his fingers dipped between your thighs, then his arm locked and you couldn’t move it any further. He trailed his lips along the curve of your neck up to your ear before he whispered, “Do you really want to go there?”

Your breath hitched, and you leaned against him, “yes…”

His hand didn’t delve between your thighs as you thought they would, instead, he grabbed your hip and twisted you around. His lips crashed into yours in a bruising kiss that made your head spin. Your hands gripped at his shirt, trying to pull him closer. You got your wish when, without breaking the kiss, he slid his hands down your thighs and pluck you from the ground like you weighed nothing.

You felt his arousal pressed against your core and you let out a desperate noise, gripping his shoulders and arching into him.

The kiss was desperate, eager, and **hot**. He was in total control, and all you could do was cling to him, breathlessly. You surprised yourself when you ground your hips against his, trying to get every bit of stimulation you could. You wanted him to touch you. You wanted him. Oh. Fuck. You wanted him so badly.

You felt him turn, his strong arms keeping you tight against him as his lips moved down to your neck. Tiny hot bites, kisses, and long sensual licks along the curve of your neck had you _mewling_. You reached up and dragged your fingernails across his neck trying to pull him closer.

With your eyes clamped shut, the only sign that you left the kitchen was when he briefly released you with one hand to switch the kitchen light off. You had whined at the loss of contact and he chuckled and whispered, “don’t worry, I won’t be able to keep my hands off you.”

You were too lost for words.

You were reminded suddenly that, ‘ _Hey! You’ve never had sex!’_ as he placed a knee on your bed and bent to lay you down. You felt your face flush with embarrassment as he straightened and ran his hands down your thighs to your hips. There was the instinct to just curl up, so you covered your face in embarrassment. Grillby chuckled lightly, one hand leaving your thigh to gently pull one of your hands away from your face. The other hand slid beneath your sleep shirt and you felt it starting to rise.

Suddenly, anxiety shot through you and you grabbed the hem of your shirt, shoving it down and nearly yelping.

His hands flew from your body immediately, “I…did I misunderstand? Do you not want to have sex? Did I cross any lines?”

Your chest was heaving from both embarrassment and anxiety. You wanted to, you wanted him. You just…reacted. You stammered slightly as you tried to explain that to him, “uh! No! I just! I’m…I! I want to! I just!….Nervous?”

He sat back, staring down at you, “…the fuck? Why?”

“Why?” you parroted back, peeking through your fingers, you swear your face was as red as a tomato, “B-because! I’ve…never…done…this?”

That seemed to surprise him. You hadn’t ever mentioned it to him before, just said you weren’t ready to have sex with _him_ yet…not in general. Maybe you should’ve? Before he was kneeling between your thighs with his shirt all rumpled.

“Never?”

You shook your head, curling a bit further in on yourself.

“Ever?”

Another head shake, recovering your face this time with your other hand.

“You’ve had other partners before?”

“Not sexually,” you mumbled, embarrassed and sat up. You couldn’t meet his eyes. This was…becoming mortifying. You _knew_ Grillby had tonnes of experience in this. If Sans was to believe, he’s had trysts with nearly every single monster from the part of the Underground they were in. That’s not even to mention how many humans he’d taken to bed. Hell, that was one of the reasons you weren’t into him when he had first attempted to try to take you to bed.

Yet, here you were. Unexperienced and too self-conscious to let him see your chest…even if you were wearing a tank top and he’d felt it before while the two of you were making out.

Grillby still hadn’t said anything, and his hands hadn’t moved from where they were hovering away from you.

So, you did what you did in any moment of anxiety. You started to ramble, “I mean unless you count like fumbling in the dark, heh…plenty of that but not like with the lights on or…you know the man being made of fire. I get it if you’re weirded out because you’ve been with plenty of people who probably all have had more experience than me. I mean, I’m in my twenties and y’know had full-on sex? OR whatever you want to call it-“

That seemed to jerk Grillby out of whatever stupor he was in, and his hands moved back to your hips. You jumped at the touch and cut yourself off, staring up at him finally. “Fumbling in the dark means what?” Grillby asked, “Simply touching each other? Or was their…what is it humans call it? Oral?”

You blushed, “J-Ju….just touching…”

He nodded, his thumb gently moving in circles over your hip bone. “I’ve never been with someone who hasn’t been with anyone,” Grillby admitted, “but, I guess I’ll just use a different tactic.”

“Uh…w-what?” you said, looking down at his hands and swallowed.

“Is this okay?” he asked, sliding his hand down before slipping them back up beneath your shirt. Your face darkened, and you nodded. He stopped, “gotta say ‘yes’ or some shit like that.”

“Y-Yes.”

Slowly, he pushed your shirt up and you made a squeak of a noise just before it got to your breasts. He paused again, “Lay down for me.”

You slowly leaned back, resting on your elbows. He smirked at you before bending down and pressing a kiss to your stomach. You jumped slightly, but you felt your toes curl slightly. “Is this okay?” he murmured against your skin making your stomach tighten and your thighs tighten around his hips.

“Y-Yeah…”

“Mm…good,” he said sending you a grin, before trailing his hot tongue up. You bit your lip gently, stifling a breathy little moan that threatened to spill from your lips. You saw the corner of his mouth twitch up further at the sound. His fingers trailed up your sides and gently pushed your shirt over your breasts. You flushed dark, but instead of grabbing at your shirt, you merely fisted your hands in your sheets. 

His mouth returned to your skin, continuing the path up between your breasts to your neck. The fabric of his shirt brushed against your nipples and you arched against him with a soft gasp. He moved slow, trailing hot kisses up the curve of your neck, along your jaw, and finally capturing your mouth again. This kiss was unlike the other in that it was _slow_. Slowly stealing your breath, and your thoughts. You abandoned clutching the sheets in favour of caressing his jaw.

You were always amazed by how solid he felt to you, despite being made of fire, and this was no different. The kiss was deep, and he was taking his time, pulling away only to let you gain your breath again before returning to steal it back once more. Your fingers slowly traced his jaw, curling around to the back of his head, feeling the flames dance between your fingers.

Grillby pulled away fully, holding himself above you just barely. Just enough that with every breath his shirt would brush against your exposed skin which sent delicious shivers through your body, along with the ache to be touched.

Your face was still burning with self-conscious embarrassment, but you were beginning to relax. His gaze drifted down your body, and then slowly back up to your face. “You’re beautiful,” he stated as if it were a fact. You went to blurt out a denial, but before you could his head dipped down and his tongue flicked over your nipple. A tiny gasp left your mouth and your back arched.

“Is that good?” Grillby asked, and when you glanced down he was smirking. He knew it was.

“Y-Yes.”

The trail of kisses returned, but instead of heading over, his kisses led down. The lower he got, the longer he lingered his mouth against your flesh. The more he’d nip and leave open-mouthed kisses. His fingers curled around the waistband of your shorts, and then his eyes opened and met yours. “May I?”

“P…P-Please,” you near moaned. Your body was on fire from just him kissing you and your skin, yet excitement made you lift your hips before he even moved which had him grinning. The time it took him to pull down your sleep pants was excruciatingly slow, and as he tossed the fabric aside, you were already moving to cover yourself up. Grillby didn’t move to stop you, just slid his hands along your thighs, eyes raking in your body.

“I’m feeling a bit overdressed,” he said, voice light and teasing.

You reached up, ignoring the slight shake to your hands and went to unbutton his shirt but his hands caught yours.

“We don’t have to if you don’t want to,” he said, his voice completely serious, “I don’t want you to feel like you need to do this, any of this. We don’t need to rush…”

“I want to,” you replied, and sat up. Your tank top slipped down, reminding you of its presence. In a sudden surge of bravery, you slipped it over your head and tossed it into the abyss of your bedroom. “I want _you,_ ” you added, pouring your feelings into the words and watched as his face softened. When you went to unbutton his shirt again, he let you, and you took your time. There was no rush, and that reminder just…soothed some of your anxieties.

That didn’t stop the blush on your face, or the fact that you had drawn your knees together to give yourself a bit of coverage.

Grillby always slept without his shirt on, so you already knew the feeling the almost muscular planes of his chest beneath your palms as you slid your hands up his chest. You slid his shirt down his arms, allowing yourself just to feel him and momentarily have full control. Grillby’s hands were just slowly sliding up and down your thighs.

You kissed where his clavicle would be if he was human and then nuzzled against his jaw lightly.

“You’re still overdressed,” you whispered, not trusting your voice to get any higher.

When he stood up, you were expecting him to undo his belt, but instead, he hooked his arms under your knees and pulled you to the edge of the bed. You gasped in surprise and pushed yourself up onto your elbows. As he lowered himself to his knees, your mind began going a mile a minute.

Your mind stopped when he kissed the inside of your thigh, his hot white eyes watching your face intensely.

You ceased to be able to think of anything but his mouth as he nipped, kissed, a hot trail down your thigh. Just when you thought he was going to finally, _finally_ touch your core, he switched to the other thigh. A smirk on his face as he paid equal attention to the soft flesh. You groaned a little out of frustration, which made him nip just a bit harder eliciting a breathy moan from you.

Then?

He met your gaze and drew his hot, hot tongue slowly along your dripping wet core.

“Oh-…oh, fu… _fuuuuck_ ,” you huffed out, covering your face and falling onto your back, unable to look at him anymore.

Grillby had you a trembling, panting, moaning mess in mere moments…and he barely had to do anything. You were already so worked up from him just touching you earlier and the kiss…and Grillby knew what he was doing. His tongue never gave you the same stimulation for too long, changing it up just before you got used to it.

“You’re so fucking hot,” Grillby groaned against you.

“T-That’s…my-..oh god…my line,” you managed to groan out, and he huffed out a laugh against your clit making your hips buck slightly.

He stopped and you actually whined in frustration, your hand creeping down to try to give yourself the sweet pressure that your body _craved_. However, Grillby beat you there, his fingers stroked your folds and you felt yourself quivering in anticipation. He was careful and slow, as he slowly slid a finger into you. All you could do was gasp and pant, and cover your face as he started to pump.

There was a pressure building up in your stomach that was familiar, especially when he brought his other hand to circle your clit at a deliciously satisfying pace and you soon were bucking your hips to get _more_.

“Grillby,” you moaned, “Do-Don’t….s-s…stop.”

“Anything for you,” he joked, and you jolted up onto your elbows when his fingers curled and hit a spot within you. The loudest moan ripped from your lips, and your body began to quake, and when he pressed against the spot again you saw stars as the pressure build-up seemed to snap and you let out a cry.

Grillby stroked you slowly, easing you through your orgasm as you let out little moans and writhed against his hand.

“F…fuck,” you huffed out as his fingers left you feeling empty, and you glanced down at him in time to see him slid his fingers into his mouth and wink at you. Your blush came back and you covered your face once again.

He chuckled, and you heard him stand up, “For someone whose never fucked before, you really know how to ride my fingers.”

You blushed hard at that, “I-I…It’s not like I’ve…y’know…never…” you gestured vaguely downwards, and his smirk grew.

“Finger fucked yourself before?” he supplied and you nodded shyly, “Now I hope you were thinking of me when you touched yourself, and if you weren’t, you will be now.”

“O-Of course!” you blurted out, and then covered your face once more as he laughed, “You’re my boyfriend!”

The bed shifted as he leaned against it between your legs, and you peeked up at him. His hands were on your hips, and he was giving you a much softer look than you anticipated. It filled your heart with affection, and you reached an arm up towards him wanting him close to you. Grillby wasted no time pressing himself back on top of you and kissing you breathless.

When you felt how _hard_ his arousal was against your thigh, all your thoughts were about how much you wanted him inside you. Your fingers found his belt and unbuckled it swiftly. Grillby chuckled against your lips and straightened once more, letting you unbutton his pants and push them down. To find…no underwear.

Honestly, the fact that he wasn’t wearing underwear startled you considering his flaming cock sprung out. You might’ve jumped in surprise, and Grillby definitely made an attempt to stop himself from laughing at you. Which, any other time would’ve made you scowl at him, but this just made you blush and become embarrassed once again.

“Sorry.“

“For what?” Grillby snorted, “Being shocked by my dick?” he shrugged, “Just strokes my ego.”

“S’not the only thing that’s been stroked-“

“Don’t make me think of Sans by making puns or talking like him, please,” Grillby interrupted you and shivered, which just made you giggle a little.

You relaxed much faster this time from the embarrassment as his lips captured yours again, nudging you back down onto the bed. The kiss was languid, and his hands gently caressed your skin, slowly building you back up in a way that you hadn’t been before. Normally you’d have stopped if you had bothered long enough to get yourself off, and your body was already starting to tremble in anticipation for what was to come.

“You look so fucking beautiful underneath me,” he murmured against your lips, and the words just added fuel to the fire. You arched against him, pulling him closer wanting to feel him against you. His cock brushed against your folds and you moaned into the kiss. “The fucking noises you make are so stars damn sexy…” he groaned as he pushed himself off you slightly. You attempted to follow him, missing his solid heat but he rested a hand on your stomach and kept you pinned to the mattress. His eyes drifted over your body and your face heated right back up.

“We’re never having sex with the lights on,” Grillby said grinning, “Purple is your colour.”

You blushed hard again, glancing down in realization that you were completely purple since his flames were the only source of light in your room.

“I think this is my new favourite view of you,” he added, “dishevelled, fuckable…”

Your hips bucked slightly against him, feeling the press of his cock against you. A sharp smile stretched over his face, before he shifted, pressing your knees wider, and slowly slid his cock up and down your slick folds. You let out a moan and writhed at the feeling, and subsequently groaned when he stopped moving.

“We can stop at any point,” Grillby reminded you, “Just tell me to and I’ll stop. No matter what, no matter when. If you need a break, we can take one. If you want to stop completely, we’ll stop. If anything hurts you tell me immediately. This shit’s all about trust, got it? I need to trust that you will tell me when you don’t like something, and you need to trust me that I’ll stop.”

“I trust you,” you said immediately, “Please, Grillby…”

Grillby leaned down and kissed you, just once, more of a peck before he straightened.

It was a bit uncomfortable as he slowly slid the tip of his cock inside of you, and you wriggled slightly to try to dissuade the feeling. The stretch was new but not as painful as you expected. Even as he slowly pushed inside in tiny languid thrusts. He was taking his time, hands slowly exploring your skin, and eyes pinned to your face. You might’ve gotten embarrassed by him studying your face so intensely, but you were more focused on the feeling of being stretched and filled.

He stopped, his hips pressed firmly to yours and you finally realized what people meant when they said they felt full.

All the ideas of your first time needing to hurt went right out the window. You didn’t know if it had something to do with his magic, or how fucking wet you were for him, or what. But you didn’t care.

All you wanted was for him to _move_.

You gave an experimental roll of your hips, and Grillby _moaned_.

You blushed for him, but he didn’t seem embarrassed in the slightest.

He pulled out slowly and then pushed all the way back making you arch at the incredible sensation. His pace was slow, each thrust was full, and his hands never stopped stroking your body. Your nerves were on fire, and each touch just added to the already building pressure inside of you. As the tension built and built, you found yourself gradually lifting your hips to match his pace, eliciting grunts and moans of pleasure from Grillby.

“Stars, you….fuck…feel so fucking tight…” he groaned and gave a small circle of his hips when he was fully buried inside you making you gasp in delight.

As his pace picked up, he hooked his arms beneath your knees and bent over you, pressing your legs closer to your chest. It changed the angle and you quickly slid your arms around his neck as it hit just the right spot deep inside you. A breathless moan pooled from your lips and then he was kissing you again.

The pace dissolved quickly, and when he reached between you to circle your bundle of nerves, you came undone quickly. Your entire body clenched tightly around him, and you saw stars. His name tumbled from your lips in a mantra as he rode through your orgasm.

He pulled completely out of you once your body had relaxed once more, and his hand dropped to his cock, stroking it at the rough pace he’d been pumping into. You watched as his head looked around for something…probably to cum into.

Your face was on fire, but you pushed yourself up onto your elbow and reached forward with your other hand to brush against the tip of his cock.

He wasn’t expecting it, and let out a strangled, “oh _fucking_ \- fuuuuck,” and came over your stomach and chest.

It was hotter than you expected, both in temperature and the act. Grillby released himself, and his eyes roamed over your body before meeting your own. “I do hope that’s what you meant to happen,” he said the flames of one side of his head rose slightly.

“Y-Yeah,” you stuttered out, embarrassed, “Uhm…w-was…that..okay?”

Grillby dropped his gaze back down to your stomach, then back up to you. “More than,” he chuckled, “I take back what I said earlier…this is my new favourite view of you.”

You covered your face again, “Oh my god.”

That made him laugh and his bent down to kiss your neck, “Now the least fun part of sex. Clean up.”

“Here I thought it would be your favourite part,” you muttered, as he stepped back from you. You opened your eyes and accepted the hand he was holding out for you.

“I despise cleaning.”

“Yet you do it all the time,” you teased back, ignoring the way your face was still burning from embarrassment.

“Because your apartment is filthy,” he responded back in that oh so familiar way, leading you towards the bathroom. You smiled and slid your hand into his, he brought up your hand and kissed it. You were glad that he was your first…and surprised at how gentle he’d been.

**Author's Note:**

> If you want to request a UF!Grillby one-shot (or really any one-shot) you can do so at my tumblr linked below! Or if you simply want to just request UF!Grillby, just leave the prompt in the comments below. I can't promise I'll do every request sent, however.
> 
> [As always; here's my tumblr!](https://myownpersonaldemons.tumblr.com/)


End file.
